28 BULLETIN 124, U. S. DEPARTMENT OE AGRICULTURE. 
level and having an average annual rainfall of probably less than 
2 inches, while the Salt Biver Valley has an elevation of some 1,200 
feet and an annual rainfall of about 8 inches. A study of the out- 
breaks of Eurymus in the two valleys shows them to vary inversely 
with the rainfall. In the dryer Imperial Valley the outbreaks are 
more numerous and severe and the resultant damage is greater than 
in the Salt Eiver Valley with its greater rainfall and its longer 
period of humid weather during the hot summer months. 
The worms when first attacked take on a lighter green color and 
become sluggish; but in a few hours they change to a brownish 
black and melt down into a decaying mass. A first sign of the 
breaking down of tissues may often be noted when the worm is still 
active, a slight exudation at some small broken place, usually in 
front ; and the writer has noted specimens with the anterior end 
blackened and the posterior end still slightly moving, showing that 
life was not yet extinct. The attack upon a pupa is similar, except 
that the stronger pupal covering usually prevents the melting down 
of the specimen, and later the decayed contents of the interior dry 
up, leaving the empty black shell still intact. 
BIRDS AND DOMESTIC FOWLS. 
Few records are available showing the relation of wild birds to 
the alfalfa caterpillar. Several times the writer has observed birds 
with larva? in their bills, but he was unable to capture these, not 
having the necessary firearms. Domestic fowls, however, play an 
important part in the history of this insect. In alfalfa adjoining 
farmhouses where chickens or turkeys have the run of the field one 
rarely finds alfalfa caterpillars in numbers, whereas fields adjoining 
chicken lots inclosed with wire fence, keeping the poultry out of the 
alfalfa, suffered severe damage. In Mr. E. N. Wilson's notes for 
1912 he reports that " Mr. Carlos Stannard, living 4 miles northeast 
of Glendale, Ariz., killed a young rooster and found 24 Eurymus 
larvae in the rooster's crop." Mr. T. Scott Wilson was informed by 
Mr. Everett, living near Tempe, that he and his wife had found a 
dozen larva? in a chicken's crop, the chickens having access to an al- 
falfa field growing near the house. By the same observers, turkeys 
have been noted feeding greedily upon the larvse, a flock in travel- 
ing across an alfalfa field eating hundreds of them. Mr. T. Scott 
Wilson, on July 21, 1913, at Chandler, Ariz., made the following 
note: 
I observed one dozen turkeys in a half acre of alfalfa on the lots of the 
United States power house feeding upon Eurymus larvae. The alfalfa 
is about 12 inches high and is tender. I find only a few Eurymus feeding 
upon this alfalfa, while in a large field just across the fence the alfalfa is 
almost destroyed, except that in that portion next to the house where the tur- 
